Key device and multi-legged supporting balance bar structure thereof

Abstract

A key device includes a base plate, a key cap and at least one balance bar. The at least one balance bar is with a tabular body and is disposed between the base plate and the key cap. The at least one balance bar has an elongated rod and a plurality of supporting legs connected to the elongated rod and protruded from a lower edge of the elongated rod. The elongated rod is connected to the key cap. The plurality of supporting legs is connected to the base plate.

What is claimed is: 
     
       1. A key device, comprising:
 a base plate; 
 a key cap; and 
 at least one balance bar with a tabular body and disposed between the base plate and the key cap, the at least one balance bar having an elongated rod and a plurality of supporting legs connected to the elongated rod and protruded from a lower edge of the elongated rod, the elongated rod connected to the key cap, and the plurality of supporting legs connected to the base plate. 
 
     
     
       2. The key device as claimed in  claim 1 , wherein a first pivoting portion is formed on the elongated rod, a second pivoting portion is formed on the key cap corresponding to the first pivoting portion, the first pivoting portion is pivoted to the corresponding second pivoting portion, each of the plurality of supporting legs has a first sliding contact portion, the base plate is disposed with a plurality of second sliding contact portions corresponding to the first sliding contact portions which are slidably disposed on the corresponding plurality of second sliding contact portions. 
     
     
       3. The key device as claimed in  claim 2 , wherein a plurality of the first pivoting portions is formed on the elongated rod, each of the first pivoting portions contains a pivot axis with a cylindrical shape, a perforation is respectively disposed on the elongated rod adjacent to each of these pivot axis, a plurality of the second pivoting portions is disposed on the key cap, each of the second pivoting portions contains a seat body protruded from a bottom surface of the key cap and a pivot hole disposed in the seat body, these pivot axes are respectively pivoted in the corresponding pivot holes, and the seat bodies is respectively received in the perforations. 
     
     
       4. The key device as claimed in  claim 1 , wherein a width of a mid-position is approximately the same a width of a position at both sides of the elongated rod. 
     
     
       5. The key device as claimed in  claim 1 , wherein a width of a mid-position is larger than a width of a position at both sides of the elongated rod, such that a reinforcement portion is formed at the mid-position of the elongated rod, and the reinforcement portion is located near the mid-position of the elongated rod between the two supporting legs. 
     
     
       6. The key device as claimed in  claim 1 , wherein the supporting legs are disposed on the balance bar, and formed into a left and right symmetrical form along an intermediate point of the balance bar in a length direction. 
     
     
       7. A multi-legged supporting balance bar structure of a key device is with a tabular body, and has an elongated rod and a plurality of supporting legs connected to the elongated rod and protruded from a lower edge of the elongated rod. 
     
     
       8. The multi-legged supporting balance bar structure of the key device as claimed in  claim 7 , wherein each of the plurality of supporting legs has a first sliding contact portion, and a first pivoting portions is formed on the elongated rod. 
     
     
       9. The multi-legged supporting balance bar structure of the key device as claimed in  claim 8 , wherein a plurality of the first pivoting portions is formed on the elongated rod, each of the first pivoting portions contains a pivot axis with a cylindrical shape, a perforation is respectively disposed on the elongated rod adjacent to each of these pivot axes. 
     
     
       10. The multi-legged supporting balance bar structure of the key device as claimed in  claim 7 , wherein a width of a mid-position is approximately the same a width of a position at both sides of the elongated rod. 
     
     
       11. The multi-legged supporting balance bar structure of the key device as claimed in  claim 7 , wherein a width of a mid-position is larger than a width of a position at both sides of the elongated rod, such that a reinforcement portion is formed at the mid-position of the elongated rod, and the reinforcement portion is located near the mid-position of the elongated rod between the two supporting legs. 
     
     
       12. The multi-legged supporting balance bar structure of the key device as claimed in  claim 7 , wherein the supporting legs are disposed on the balance bar, and formed into a left and right symmetrical form along an intermediate point of the balance bar in a length direction.